MRA Mapping and Selective Embolization of a Large Uterine ... CaseReport MRA Mapping and Selective Embolization

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  • Case Report MRA Mapping and Selective Embolization of a Large Uterine Cavity Pseudoaneurysm at 20 Weeks of Gestation

    Jean V. Storey ,1 Timothy B. Dinh,2 Deirdre M. McCullough,1

    Steven H. Craig,2 and Christian L. Carlson2

    1Department of Obstetrics and Gynecology, Brooke Army Medical Center, 3551 Roger Brooke Drive, Fort Sam Houston, San Antonio, TX 78234, USA 2Department of Radiology, Brooke Army Medical Center, 3551 Roger Brooke Drive, Fort Sam Houston, San Antonio, TX 78234, USA

    Correspondence should be addressed to Jean V. Storey; jean.v.storey.mil@mail.mil

    Received 16 January 2018; Accepted 26 March 2018; Published 7 May 2018

    Academic Editor: Akihisa Fujimoto

    Copyright © 2018 Jean V. Storey et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

    Antepartum uterine cavity pseudoaneurysm rupture can cause massive hemorrhage with high maternal and fetal mortality risk. Invasive placentation can predispose to vascular malformations. We present a novel use of macrocyclic intravenous contrast- enhancedmagnetic resonance angiography for preprocedure planning followed by selective low radiation embolization of a uterine cavity pseudoaneurysm in the setting of invasive placentation at 20 weeks of gestation. To our knowledge, this is the first reported case of uterine cavity pseudoaneurysm successfully mapped with MRA and treated with embolization at 20 weeks of gestation.

    1. Introduction

    Uterine surgery can predispose to future pregnancy com- plications to include abnormal placentation and vascular lesions such as arteriovenous malformations and fistulas and pseudoaneurysms [1, 2]. Hormonal and hemodynamic changes also play a role in development of vascular lesions in pregnancy [3]. Vascular lesions may present with life- threatening hemorrhage. Low patient risk and relatively low cost make ultrasound the screening method of choice with contrast angiography used for problem solving, treatment planning, and therapeutic intervention [1, 4]. Historically, treatment required hysterectomy, but arterial embolization currently offers a less invasive, fertility-sparing treatment option with a low complication rate [1, 5]. We report a novel use of dynamic IV contrast-enhanced magnetic reso- nance angiography (MRA) for further characterization and treatment planning/mapping of a uterine cavity pseudoa- neurysm in a 20-week gravid female followed by low radia- tion embolization of feeding arteries, resulting in successful maternal and fetal outcome.

    2. Case Presentation

    A35-year-old gravida 4 para 3with a history of three previous cesarean deliveries presented at 16 weeks 6 days of gestation for follow-up ultrasound of perigestational hemorrhage seen at 10 weeks and 4 days. A large uterine cavity pseudoa- neurysmmeasuring 4.2 × 3.8 × 3.7 cm and appearing to arise from abnormal placentation at the previous cesarean scar was identified (Figure 1). Repeat ultrasound six days later revealed a normal active fetus in breech position compressing the pseudoaneurysm upon contact. An unenhancedMRI one week later confirmed a 4 cm hypointense lesion projecting into the lower right uterine cavity at the inferior margin of the placenta (Figures 2 and 3). Management options were discussed to include conservative imaging observation versus embolization. Due to high maternal mortality risk from spontaneous hemorrhage, elective termination was also discussed but was rejected by the patient.

    A novel use of dynamic time-resolved contrast-enhanced MRA utilizing a functional MR urography protocol� was performed for enhanced characterization of feeding arteries

    Hindawi Case Reports in Obstetrics and Gynecology Volume 2018, Article ID 3610492, 7 pages https://doi.org/10.1155/2018/3610492

    http://orcid.org/0000-0003-3716-6760 https://doi.org/10.1155/2018/3610492

  • 2 Case Reports in Obstetrics and Gynecology

    Figure 1: Follow-up ultrasound at 16 weeks and 6 days of gestation reveals a vascular malformation (arrow) at the lower uterine segment with swirling flow within the malformation consistent with a pseudoaneurysm.

    Figure 2: Coronal T2-weighted image of the pelvis at 18 weeks of gestation demonstrates a hypointense round structure (arrow) at the lower uterine segment infringing upon (and invaginating into) the gestational cavity. Fetal knee abuts and deforms the lesion.

    (a) (b)

    Figure 3:Maternal coronal (sagittal fetal) T2-weighted image of the pelvis (a) at 18 weeks of gestation with similar fetal positioning in relation to the lesion on ultrasound (b) as if the fetus (arrow) is sitting (or bouncing) on the lesion (arrowhead). Note the Yin/Yang swirling flow on color Doppler.

    and treatment planning/mapping [6]. The specific MRA parameters utilized can be viewed in detail online at www.chop-fmru.com. Although not FDA-approved for a second trimester fetus, Gadobutrol� contrast agent was selected to reduce risk of gadolinium deposition. Gadobutrol is a macrocyclic agent that imparts strong chelation of the substrate to gadolinium. It reduces potential toxicity from free gadolinium and, at the time, was the only FDA-approved

    agent for patients below 2 years of age (down to 37 weeks of gestation). Gadobutrol was dosed per the manufac- turer’s protocol with recommended weight-based dosing of 0.1–0.3mmol/kg. Informed consent was obtained for this unique use of MRA at 20 weeks of gestation.

    MRA revealed two suspected feeding vessels: a branch off the right ovarian artery parasitized to the uterine arcuate artery (Figure 4) and a branch off the right uterine artery

    http://www.chop-fmru.com

  • Case Reports in Obstetrics and Gynecology 3

    (a) (b)

    (c)

    Figure 4: Coronal T1 MRA and 3D surface rendered reconstruction (Vital Images� postprocessing software) of the aberrant right ovarian artery branch feeder at 19 weeks of gestation. The proximal right ovarian artery originates from the aorta and courses into a tangle of vessels (long arrows) in the right abdomen ((a) and (c)) before penetrating the myometrium (curved arrows) ((b) and (c)) and extending caudally (short arrows) as an arcuate artery to the lesion. Pseudoaneurysm (arrowhead), uterine cavity (chevron), and aortoiliac vessels. Draining vein (blue).

    parasitized to the uterine arcuate and radial arteries (Fig- ure 5). The lesion now measured nearly 5 cm. Abnormal placentation was again suggested.

    Fetal and maternal risks of embolization were reviewed with the patientwho strongly desired intervention. A conven- tional arteriogram performedwith iodinated contrast diluted 50/50 with normal saline demonstrated a prominent right ovarian artery with origin off the aorta at L2/3 as seen on MRA. Prominent hypogastric arteries were noted along with a subtle blush in the right pelvis suspicious for the target lesion. A right ovarian arteriogram revealed a prominent tortuous right ovarian artery similar to that seen on MRA (Figure 6). Amore distal right ovarian arteriogram suggested a blush of contrast in the pelvis suggestive of the target lesion. The right ovarian artery was then embolized with coils (Fig- ure 6). A right hypogastric arteriogram revealed a prominent right uterine artery and a large ovoid lesion opacifying with contrast consistent with the target lesion (Figure 6). The right uterine artery was then embolized. Postcoil imaging revealed no lesion opacification (Figure 6). In an effort to

    reduce radiation dose to the fetus, all angiographic runs were performed without digital subtraction. The required 30.4 minutes of fluoroscopic time resulted in a total radiation dose of only 490mGy.

    Ultrasound interrogation the next morning revealed no flow within the lesion (Figure 7). Repeat ultrasound 24 hours later, however, showed recurrence of small blood flow into the lesion, with a significant decrease in lesion size to 3.3 cm, which remained stable prior to discharge 4 days later (Figure 8). Serial ultrasound examinations throughout the duration of the pregnancy demonstrated appropriate interval fetal growth.Thepseudoaneurysmprogressively decreased in size, measuring 1.4 × 2.0 cm just prior to delivery (Figure 9).

    The patient presented with premature rupture of mem- branes at 33 weeks. Cervical changes and painful contractions necessitated an urgent prophylactic cesarean delivery 13 weeks after embolization. On attempt to deliver the placenta, it was adherent to the uterus, consistent with invasive pla- centation. The placenta was left in situ and a supracervical hysterectomy was performed. The patient was discharged on

  • 4 Case Reports in Obstetrics and Gynecology

    (a) (b)

    Figure 5: (a) Sagittal oblique reconstruction of T1MRA and 3D surface rendered image (Vital Images postprocessing software) (b) of uterine artery feeder (arrows) to the pseudoaneurysm (arrowheads). Uterine cavity (chevrons).

    postoperative day 3. The baby was admitted to the NICU secondary to prematurity and discharged home in stable condition at 19 days of life.

    3. Discussion

    Repeat cesarean delivery increases the risk of abnormal placentation and predisposes to vascular malformations [1, 2]. Hormonal and hemodynamic changes in pregnancy contribute to development of vascular lesions [3]. Pseudoa- neurysms develop when trauma, degeneration, or necrosis causes a defect or weakening in the arterial wall through which blood escapes, forming a contained hematoma with or without a thin wall of adventitia and in continuity with the artery that supplies continuous blood flow. Absence of a three-layered arteria